Circularly polarized quadrifilar helix array using a sequentially rotated feed network

A circularly polarized 2×2 antenna array suitable for portable L-band satellite data terminals is presented. The array is composed of short resonant quadrifilar helices fed by a corporate microstrip feeding network fabricated in low cost FR4 substrate. The helices are printed on flexible PCB material. A bandwidth increase compared to a single quadrifilar helix is demonstrated through the application of sequential rotation. Discussion of the array as an antenna option for portable satellite data terminal is included considering the low height of the helices used.